Robin Williams Via TwitterA few weeks back, Kelly Clarkson tweeted a photo of herself with Robin Williams, posing on the set of a CBS comedy pilot called The Crazy Ones. Turns out she made a cameo as herself in the pilot, and now that CBS has now picked up the show for the fall, we'll be able see her. A sneak preview, however, is available online now.

The Crazy Ones is set in Chicago, and is about a father and daughter, played by Williams and Sarah Michelle Gellar, who both work in advertising. In the pilot, they try to persuade Kelly to sing a McDonald's commercial, but she tells them she wants to change her image and "sing about sex."

"They said I wouldn't have to act, 'cause I suck at acting," says Kelly in the preview. "They said, 'Well, you're playing yourself.' But it's not myself!"

Kelly says she "lost" it during a scene where Robin Williams and another cast member try to come up with ways that Kelly can sing about sex, and still sing about McDonald's. Next, we see her in the studio singing a song called "It Ain't the Meat It's the Motion" -- which is a real song, by the way -- and simulating being in the throes of sexual passion.

The show's executive producers say that Kelly was "amazing" in the episode, adding, "She rocked it!"